Induction of neuro-inflammation by activating microglial cells and its impact on survival of dopaminergic neurons

Aim: The aim of the current study was to isolate microglial cells from neonatal rat brain, activate the cells using lipopolysaccharide (LPS) and examine the effect of the inflammatory factors that they express on dopaminergic (DAergic) neurons.
mixed glial cells were isolated from 1-3 day rat neonatal brains and then microglial cells were extracted from them. Upon treatment of the cells with LPS, their conditioned media (CM) were collected. DAergic SH-SY5Y cell line was seeded in 96-well plates and fed with the collected CM. The rate of viability and apoptosis of the neuronal cells was examined using MTT and apoptosis tests and the data were analyzed statistically.
Ten to thirteen days after isolation, mixed glial cells were composed of three types: astroglia, oligodendrocytes and microglia. Microglia were floating while semi-attached to the surface. Twenty four hours post-isolation, these cells were transferred to and cultured in separate dishes where they formed spindled and ramified phenotypes. At this stage, the cells were treated with LPS to be activated. This activation was demonstrated by morphological changes from spindle-like form to amoeboid form, detection of increase in NO expression using Griess test and induction of inflammatory iNOS and TNF-α gene expression. Also teatment of SH-SY5Y cell line with conditioned medium of activated microglia led to both apoptotic and necrotic cell death.
LPS-mediated activation of microglia results in overexpression of neuroinflammatory markers. The overproduction of these markers results in both apoptotic and necrotic cell death amongst DAergic neurons via neuroinflammation.